Data networks such as the Internet, enterprise data networks, mobile broadband networks, and cloud networks, have become an integral part of our lives. We use data networks to obtain news, gather product information, reserve a table for dinner, submit a payment, purchase a good, read a book, find a map, make or receive phone calls, conduct or join a conferencing event, participate in a meeting, work on a document, approve a promotion, chat with a friend, watch television and videos, book a plane ticket, and do many other things in our normal lifestyle or work style. Typically we use a host computing device such as a smartphone, a tablet, a laptop, a personal computer, or a smart television, to communicate with an application service server to perform one or more tasks over a service session. The server is typically a computing device. The service session includes a plurality of data packets routing through a data network.
Currently, a host device sends data packets through the data network to the server device. Conversely the server device sends response data packets through the data network to the host device. The network path, in which data packets traverse from the host device to the server device, is pre-set by the data network using one or more network forwarding protocols such as Internet routing protocols, Ethernet protocols, and other layer 2 or layer 3 protocols. The network path typically consists of network switches and routers.
The data packets of the service session is usually subjected to a number of inspections and controls before the data packets are delivered to the destination host device or server device. These network inspections and controls are performed by special network application appliances. There are security related inspections and controls such as IDS (intrusion detection system), firewall, lawful interception, malware detection and many others. There are company specific security inspections and controls that detects for document transfer, email scan, user access control, and others. There are network traffic inspections and controls such as bandwidth management, quality of service, tariff control and others. There are network monitoring inspections and controls such as rating, sampling, packet tracing and others. There are network optimization inspection and controls such as content caching, data de-duplication, email access optimization, and others.
It is very common for a network administrator to deploy one or more such network inspections and controls to a service session. In order for the inspection and control to function properly, a network administrator must know the preset network path of the service session and deploy the network application appliance along the preset network path. To assure the service session is subjected to the inspection and control function of the deployed network application appliance, the network administrator also needs to engineer and plan the data network such that any changes, due to a change of the network switches and routers, from the preset network path to a new preset network path, the new preset network path needs to include the deployed network application appliance.
Additionally, network inspection and control functions are usually computing and/or resource intensive. When their capacities are reached, the network administrator needs to deploy additional network application appliances, or utilize other less busy network application appliances in the data network. Deploying additional network application appliances requires, as mentioned above, careful planning and engineering of the data network in order for the plurality of network application appliances to share the processing or resource load, and to ensure the network paths of a plurality of service sessions to pass through the plurality of network application appliances in an evenly distributed manner. Utilizing other less busy network application appliances is often not possible as the network paths are pre-determined by the networking protocols outside the scope of the network application appliance.